Project Summary/Abstract Obesity represents a major health issue, and Pennington Biomedical Research Center is at the forefront of the fight to both understand the causes of obesity and develop treatments to combat metabolic disease. In order to effectively purse this research mission, Pennington has relied heavily on the study of mouse models of obesity using research core infrastructure that allows the specific assessment of energy balance via the simultaneous measurement of food intake, energy expenditure, substrate oxidation and physical activity. We currently have 16 funded NIH awards that depend on this equipment in some fashion. In order to continue this tradition of excellence, this S10 application seeks to upgrade and expand our capacity to support metabolic research by requesting funds to purchase a 32 cage Sable Promethion metabolic/indirect calorimetry chamber system. Our current metabolic chambers are at max capacity, require long wait times, and the older Oxymax system is functionally limited and practically beyond its life-expectancy. Research productivity is currently limited because demand outstrips the availability and capability of our metabolic chambers, our aging infrastructure increases the risk that eventual equipment failure will severely compromise the ability to execute funded research, our aging Oxymax system is both more stressful to the animals and functionally insufficient for many experimental goals. The purchase of a Sable Promethion system to replace the over 10 year old Oxymax would expand capacity, upgrade aging infrastructure, and allow novel science that is not currently possible with our current systems.